MD History: Add icon in top right of page when showing synced results

components/history_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <grit-part>
 
   <!-- History UI -->
   <message name="IDS_HISTORY_ACTION_MENU_DESCRIPTION" desc="Text used to identify the history entry drop-down menu for screen readers">
     Actions
   </message>
   <message name="IDS_HISTORY_BLOCKED_VISIT_TEXT" desc="Text that describes an attempted visit.">
     Blocked attempt <ph name="BEGIN_LINK">&lt;a target="_top" href="$1" id="$2"&gt;</ph> to visit a page on <ph name="DOMAIN">$3<ex>google.com</ex></ph><ph name="END_LINK">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph>.
   </message>
@@ skipping 35 matching lines @@
   <message name="IDS_HISTORY_ENTRY_SUMMARY" desc="Summary of all the fields in a history entry (time, whether the entry is bookmarked, title, and domain).">
     <ph name="TIME"><ex>3:14</ex>$1</ph> <ph name="BOOKMARKED"><ex>bookmarked</ex>$2</ph> <ph name="TITLE"><ex>PI: The Magical Number</ex>$3</ph> <ph name="DOMAIN"><ex>pi.com</ex>$4</ph>
   </message>
   <message name="IDS_HISTORY_FILTER_BLOCKED" desc="Text that shows that an entry is blocked.">
     Blocked
   </message>
   <message name="IDS_HISTORY_FOUND_SEARCH_RESULTS" desc="Message shown when zero or multiple search results are found.">
     Found <ph name="NUMBER_OF_RESULTS">$1</ph> <ph name="SEARCH_RESULTS"><ex>search results</ex>$2</ph> for '<ph name="SEARCH_STRING">$3</ph>'.
   </message>
   <message name="IDS_HISTORY_HAS_SYNCED_RESULTS" desc="The notification at the top of the history page indicating that it is showing visits synced from other devices.">
-    Showing history from your signed-in devices. <ph name="BEGIN_LINK">&lt;a href="https://support.google.com/chrome/?p=sync_history&amp;hl=[GRITLANGCODE]"&gt;</ph>Learn more<ph name="END_LINK">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph>.
+    Showing history from your signed-in devices. <ph name="BEGIN_LINK">&lt;a href="https://support.google.com/chrome/?p=sync_history&amp;hl=[GRITLANGCODE]"&gt;</ph>Learn more<ph name="END_LINK">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph>
+  </message>
+  <message name="IDS_HISTORY_HAS_SYNCED_RESULTS_DESCRIPTION" desc="Description for the notification at the top of the history page indicating that it is showing visits synced from other devices. This is spoken by the screen reader when the notification button is focused.">
+    Showing history from your signed-in devices.
   </message>
   <message name="IDS_HISTORY_OTHER_FORMS_OF_HISTORY" desc="The notification at the top of the history page indicating that deleting Chrome browsing history will not delete other forms of history stored at Google My Activity.">
     Your Google Account may have other forms of browsing history at <ph name="BEGIN_LINK">&lt;a target="_blank" href="$1"&gt;</ph>history.google.com<ph name="END_LINK">&lt;/a&gt;</ph>.
   </message>
   <message name="IDS_HISTORY_INTERVAL" desc="A history interval shown in the title. The dates are already localized strings.">
     <ph name="START_DATE">$1<ex>Wednesday, Aug. 1, 2012</ex></ph> to <ph name="END_DATE">$2<ex>Thursday, Aug. 30, 2012</ex></ph>
   </message>
   <message name="IDS_HISTORY_LOADING" desc="Text shown when we're loading the user's history">
     Loading...
   </message>
@@ skipping 107 matching lines @@
     Edit
   </message>
   <message name="IDS_HISTORY_TITLE" desc="Title for the history tab.">
     History
   </message>
   <message name="IDS_HISTORY_UNKNOWN_DEVICE" desc="On the dropdown menu for a history entry, the text that is shown instead of a device name, when the device name is not known.">
     Unknown device
   </message>
 
 </grit-part>